package org.apache.maven.repository.metadata;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import org.apache.maven.artifact.versioning.ArtifactVersion;
import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Configuration;

/**
 * @author <a href="mailto:oleg@codehaus.org">Oleg Gusakov</a>
 *
 */
@Component(role = GraphConflictResolutionPolicy.class)
public class DefaultGraphConflictResolutionPolicy implements GraphConflictResolutionPolicy {
  /**
   * artifact, closer to the entry point, is selected
   */
  @Configuration(name = "closer-first",
      value = "true")
  private boolean closerFirst = true;

  /**
   * newer artifact is selected
   */
  @Configuration(name = "newer-first",
      value = "true")
  private boolean newerFirst = true;

  public MetadataGraphEdge apply(MetadataGraphEdge e1, MetadataGraphEdge e2) {
    int depth1 = e1.getDepth();
    int depth2 = e2.getDepth();

    if (depth1 == depth2) {
      ArtifactVersion v1 = new DefaultArtifactVersion(e1.getVersion());
      ArtifactVersion v2 = new DefaultArtifactVersion(e2.getVersion());

      if (newerFirst) {
        return v1.compareTo(v2) > 0 ? e1 : e2;
      }

      return v1.compareTo(v2) > 0 ? e2 : e1;
    }

    if (closerFirst) {
      return depth1 < depth2 ? e1 : e2;
    }

    return depth1 < depth2 ? e2 : e1;
  }

}
